Antenna



June 26, 1934. o, BOHM Er AL .1,964,190

ANTENNA Filed Jan. 30, 1929 @391g their @wwwa/15j@ f( Z Z Fatented `fune 246, 1.934

UNITED sTrEs MTENT oFFlcs assignors to Telefunken Gesellschaft. fr Drahtlose Telegraphie ni. b. H.,

Berlin, Germany, a corporation of Germany Application January 3i), 1929, Serial No. 336,111 In Germany March 3, 1928 4 Claims.

In order to insure favorable conditions for the transmission of short waves in wireless telegraphy, a suggestion is found in the earlier art to dispose a number of vertical wires in one plane at 5 right angles to the sense of radiation. Such antennae are employed also successfully for the reception of short waves from a denite direction.

However, experiments have shown that the transmission of energy with horizontal antenna is more favorable than the transmission with vertical antenna. According to the present 1nvention, an antenna arrangement is disclosed which comprises a number of linear horizontal antennae which are superposed in a vertical plane. In this manner vertical bunching of the radiation is insured.

The linear antennae so used may be excited in any desired manner, for instance, in such a way that each of the horizontal antenna oscillates at one-half its wave-length and thus constitutes a simple dipole. Or else excitation may be effected so that it oscillates like a double dipole, both halves being excited cophasally.

The superposed antennae are excited cophasally by being connected to vertical feed leads a wave length apart, or a half wave length apart with reversed connections to alternate antennae.

Our invention is described more in detail in the following specication, acompanied by a drawing in which Figure 1 is one form of antenna; Figure 2 is a detail of a radiator a half wave long; Figure 3 is a detail of a radiator a full Wave long; Figure 4 indicates one method to obtain cophasal excitation; and Figure 5 is a complete antenna system the sections of which use another method of obtaining cophasal excitation.

One fundamental embodiment of the invention is illustrated in Figure 1 where the constituent linear antennae a, b, c, d, are disposed above o one another, though being fed cophasally from a common lead L.

Figures 2 and 3 illustrate diagrammatically two special cases of excitation of the horizontal antenn. In Figure 2 a dipole antenna is excited by series coupling at its middle. In 'Figure 3 a double dipole antenna is excited by coupling in the middle at one half of its Wave length. This may be considered parallel coupling, because it excites both halves of the antenna cophasally, just as l if each half was coupled as in Figure 2, and both feed lines were then connected in parallel. Of course, in either case a coupling coil may be connected in series with the halves of the antenna and across the feed line, as was indicated -5 in Figure l, and in such case the coil applied (Cl. Z-33) to Figure 2 should be merely a coupling coil, Whereas that applied to Figure 3 should be of sufficient inductance to represent a half Wave of the energy being radiated, so that it will act as a substantially non-radiating phase reversing coil. The arrangement shown in Figure 3 is the one which has been illustrated also in Figures 4 and 5, though that` shown in Figure 2 may optionally be employed.

Figure 4 illustrates a scheme for feeding energy cophasally to two systems of horizontal antenn a, b, and c, d, respectively, by way of leads m, 11, and m, 12, respectively. The desired phase is obtained in this case by equal length lines, but it will be understood that cophasal excitation of the horizontal antennae may be ininsured also in some other manner, and the dimensions of the antennae may be so chosen that they are caused to oscillate in some other multiple of a half-wave.

If the directive action of the radiation is not to be utilized primarily in a horizontal direction, but rather at a certain angle of inclination with reference to the surface of the earth, then the constituent horizontal antennae mounted superposed-fashion must be placed not in one plane, but rather in parallel phase, or in one tilted plane.

In Figure 5, four vertical systems comprising respectively the horizontal antennae al, b1, c1, d1, a2, b2, c2, d2, a3, b3, c3, d3, and a4, b4, c4, d4 are ,55 arranged in one plane, and are fed by means of the symmetrically branched leads L1, L2, L3, L4, m, n, k. The horizontal antenn of each system are suspended from a carrier cable P. The distances between the constituent horizontal antennae of each system in the arrangement as illustrated in Figure 5 amount in each case to onehalf wave, antennae b and d being connected crosswise with the feed leads, so that all of the antenn are energized cophasally. 'L9-? We claim:

l, An antenna system comprising a single, unbroken pair of vertical linear feed leads and a plurality of pairs of superposed horizontal antennae of harmonic length coupled to said feedvlo leads a multiple of a half wave length apart, alternate pairs of antenna being coupled with crossed connections for cophasal operation.

2. An antenna system comprising a single, unbroken pair of vertical linear feed leads, and al05 plurality of pairs of horizontal antenn of harmonic length coupled to the feed leads a half wave length apart, each pair of antenn being coupled to both feed leads alternate pairs of antenn` being coupled with crossed connections, for cophasal operation.

3. A directional radio system comprising a plurality of antenna sections lying in a vertical plane and spaced apart transversely of the direction of desired communication, each of said antenna sections having a single, unbroken pair of vertical feed leads and a plurality of horizontal antennae of harmonic length coupled to the feed leads a half Wave length apart, alternate antenn being coupled with Crossed connections for cophasal operation, radio equipment, and a symmetrically branched feeder system for coupling the vertical feed leads cophasally to the radio equipment.

4. A directive radio system comprising a plumaargo- 

